[media] vcodec: mediatek: Add V4L2_PIX_FMT_MT21C support for v4l2 decoder

Add V4L2_PIX_FMT_MT21C support
Signed-off-by: Tiffany Lin <tiffany.lin@mediatek.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/platform/mtk-vcodec/mtk_vcodec_dec.c

@@ -25,7 +25,7 @@
 #include "mtk_vcodec_dec_pm.h"
 
 #define OUT_FMT_IDX	0
-#define CAP_FMT_IDX	0
+#define CAP_FMT_IDX	3
 
 #define MTK_VDEC_MIN_W	64U
 #define MTK_VDEC_MIN_H	64U
@@ -48,6 +48,11 @@ static struct mtk_video_fmt mtk_video_formats[] = {
 		.type = MTK_FMT_DEC,
 		.num_planes = 1,
 	},
+	{
+		.fourcc = V4L2_PIX_FMT_MT21C,
+		.type = MTK_FMT_FRAME,
+		.num_planes = 2,
+	},
 };
 
 static const struct mtk_codec_framesizes mtk_vdec_framesizes[] = {